Dozens of federal, state and local dignitaries attended the mass, including Duluth Mayor Don Ness.

"I've been to Washington many times, and this felt real quieter, a little sorrowful, and probably it's as much in my own mind as everything, that's definitely the sense that I got," said Duluth Mayor Don Ness via Skype.

Oberstar represented Minnesota's eighth district from 1975 to 2011 and served as the chair of the Transportation Committee.

Sen. Klobuchar paid tribute to the man dubbed Mr. Transportation on Thursday, saying he was a man of purpose and grit.

He was one of those rare people who was just as comfortable in the Aurora, Minnesota Parade in khakis and tennis shoes as he was at the French Embassy," Sen. Klobuchar said.

Comfortable and curious, if you ask Sen. Al Franken.

"He was someone who was amazingly knowledgeable, because he was so curious about the world, curious in the best way, wanted to know how things worked so he could get things done," Sen. Franken said.

Colleagues say he'll be remembered for his passion and dedication for improving America's Infrastructure.

"In the majestic grandeur of stately bridges and in the cool shadows of quiet bike paths, in the hardhats hanging in the lockers of hardworking miners that go home safely at the end of the day. That's where you will find Jim Oberstar. That's where his legacy lives on," said Sen. Klobuchar.

Oberstar is survived by his wife, six children and eight grandchildren.